Plasticized composition containing a cellulose ether and a polyacrylic acid ester



Patented July 13, 1948 PLASTICIZED A CELLULO IO ACID ESTER Chessle E. Rehberg, Glensiderwilllam c. Mast,

MPOSITION CONTAINING ETHER A POLYACRYL- Philadelphia, and Charles HrFisher, Abington, Pa., asslgnors to the United States of America as representedby the Secretary oi. Agriculture No Drawing. Original application September 22,

1944, Serial No. 555,386. Divided and this application January 11, 1946, Serial N0. 840,644

4 Claims.

(Granted under the m or March a, 1883, a.

amended April 30. 1928; 370 0. G. 757) This application is made under the act of March 3, 1883, as amended by the act of April 30,

' 1928, and the invention herein described and claimed, if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes I without the payment to us of any royalty thereon.

This application is a. division of our copending application Serial No. 555,386, filed September22, 1944.

This invention relates to plastic compositions,

and more particularly to compositions comprising cellulose ethers, acrylic resins, plasticizers, and modifiers.

An object of this invention is toproduce compositions of matter in the form of permanently strong and flexible sheets or films of any desired thickness and which are flexible at low temperatures.

Another object is to provide plastic compositions which remain substantially unchanged in properties over a wide range of temperatures.

Still another object .is to provide suitable plasticizers for use with ethyl cellulose, cellulose ethers, cellulose esters, and similar derivatives of carbohydrates of high molecular weight. A further object of this invention is to provide soft, flexible and extensible compositions of matter which can be rolled, extruded, molded or otherwise worked into useful articles.

Other objects and advantages of this inventlon will appear from the following description.

We have, found that esters of hydroxy acids, either with or without the hydroxyl group of the simple esters acylated with polybasic acids, are

useful plasticizers for mixtures of cellulose ethers and acrylic resins. Among the esters which are particularly valuable for this purpose are the lactates of glycols and glycerol and those polyesters wherein alkyl or substituted. alkyl esters of hydroxy acids are acylated with polybasic acids. Esters oi the latter type may be represented by the formula (ROCOCR'R' '0) 11A wherein Ris an alkyl or substituted alkyl radical, I

50 fllms were examined for compatibility and test- R' and R." are hydrogen or alkyl groups, A is the acyl radical of a polybasic acid and n is the valence of the radical A.

As disclosed in our copending application for patent Serial No. 497,845, filed August '7, 1943, now abandoned. esters of this type may be prepared conveniently by treating an ester of a hydroxy acid with a polybaslc acid, acid anhydride or acid chloride.

For the manufacture of the plastic compositions of thisinvention, the cellulose ether, acrylic resin, and plasticizer may be dissolved in a suitable solvent and then the solvent maybe removed, as by evaporation. Another method comprises mixing the components by milling or other mechanical means. The products are flexible, tough, and rubbery, and these properties/are maintained ,atflow temperatures. The plastic compositions can be rolled, molded, extruded or otherwise shaped. For surface coatingsor impregnations, solutions of the material may be sprayed or brushed on and the solvent allowed to evaporate. Fillers, dyes, pigments, and extenders may be incorporated in the product if desired.

The cellulose ether, acrylic resin and plasticizer may be used in various proportions, though, in

general, we prefer 10-60 percent plasticizer. Generally, we also prefer to use more cellulose ether than acrylic resin. The acrylic resin may be any polymerized acrylic ester. For maximum tensile strength, we prefer polymerized methyl acrylate;

while for softer, more flexible or elastic compositions, we may use the polymers or ethyhbutyl, ethoxyethyl, or other ester. The plasticizer may be a glycol lactate, such as the mono-or polylactate of glycol, glycerol, polyethylene glycol, butylene glycol, polymethylene glycol, or other polyhydroxyalcohol; also, it may be an ester wherein a glycolic, lactic or other hydroxy acid ester is acylated with a polybasic acid, such as phosphoric, borlc, oxalic, maleic, iumaric, aconitic, itaconic, adipic, succinic, sebacic, phthalic, chlorcmaleic, alkenylsuccinic, or other such aids.

The invention is illustrated, but not limited, by

the examples given in Tables I and II. These examples were prepared by dissolving ethyl cellulose, the acrylic resln, and the plasticizer in acetone, pouring the solution into a fiat dish and allowing the solvent to evaporate. The resulting specimens were used in conjunction with a Scott Having thus described our invention. we claim: IP-2 Serigraph to determine tensile strength and 1. A plastic composition comprising a cellulose elongation at break. Brittle temperatures were ether, a polymerized ester of acrylic acid, and an determined with apparatus of the type described ester of a polyhydroxy alcohol and a saturated by Selker and coworkers (Ind. Eng. Chem., 34, alpha-hydro! carboxylic acid, said acid having 157 (1942)). A Shore durometer (type A) was less than for carbon atoms per molecule.

used to determine hardness. 2. A plastic composition comprising a cellulose Tenn I g g Plastic compositions containing ethyl cellulose and modifiers Math 1 Shore durometor Mer le 'f g Ultimate Brittle Example Plasticizer (per cent by weight) polymer, g elongation, m

. rf g Bul W After mm] seconds 1 Bis-(methyllactateg-phthalate 0 "2,000 as n 2 Bis-gmethyl lactate -phthalate 50 18 H gig) g as 3 0 5g 4 Bismethyl ..actate)-phthalate 45 11 31000 86 7e 5 Bismethyl .actate -phthalate 33 13 3,850 40 9o 6 Bismethyl lactate -phtha.late 60 0' 2,660 4o 33 7 Bismethyl lactateg-maleate o0 0' 3, 750 66 8 Bis-(methyl lactate -maleate 50 6 2,800 i 78 9 2, 3-Butyleneglyeol dilactate 45}--. 0 5, 660 85 90 10 2, 3-Butyleneglycol dilactate 0 7 2,800 78 11 do 12 2.140 9o 12 2, 3- utyleneglycol dilactate 233). 20 2, 910 50 ,e0 13 2, 3-Butylenegiycol dilactate 45). 5.5 872 40 e2 14 Castor oil (50) 0 2,660 so TB 11 ether, a polymerized acrylic acid ester, and glyc- 30 eryl lactate. Plastic compositions containing ethyl cellulose A plastic composition comprising a cellulose and mo ifie ether, a polymerized acrylic acid ester, and glycol Percent by weight lactate.

4. Applastic composition comprising a, cellulose oe fl lgge Acrylicresin Plasmw 35 ether, a polymerized acrylic acid ester, and a polyethylene glycol lactate.

' CHESSIE E. REHIBERG. 30 Methylacrylate,20.. Allyllaotate maleate,50. MAM C M 30 Methylacrylatazm. Allyl lactate adiplate, 50.

a0 Methylacrylate,20.- Allylglycolatep thalate,50. CHARLES H. FISHER. 30 Ethyl acrylate, 20 Methallyl lactate maleate, 50. 40 30 n-Butylacrylate, 20. Chloroethyl lactate sebacato, 50. REFERENCES CITED v The following references are of record in the The data in Table I include results obtained file of this patent:

with ethyl cellulose plasticized with castor oil.

The results show that the present invention may UNITED STATES PATENTS be used to prepare sheets or films having higher Number Name Date tensile strengths than that of the ethyl cellulose- 2,268,651- Eggert et a1. Jan, 6, 1942 castor oil film. 2,292,39 Mitchell Aug. 11, 1942 

